Відео

And mark the initial state

Yes, I’ve become more convinced parallel universes exist since making this video. Here’s another I made that uses music to help explain how a qubit can be in multiple parallel places at the same time: ua-cam.com/video/tHNCJuoqKu8/v-deo.html

There are lots of potential ideas! Perhaps you could investigate a quantum algorithm like the Deustch-Jozsa or Grover’s Algorithm on a quantum simulator. You could pick a principle like Superposition or Entanglement and explain it in some creative way. You could research a potential application of quantum computers or physics such as cryptography or computational chemistry. And of course you are free to use this Quantum Music video in any way you like too. Good luck with your project!

Thanks so much for your kind words, I very much appreciate it. Glad you enjoyed the video and good luck on your exam!

Why don't we just stop with the mysticism entirely and just admit we don't know what state the qubit is in? No one has ever observed a qubit in more than one state nor is it necessary to believe to explain any quantum phenomena.

Yes, you are correct that this is wrong. Looking back on my notes, this diagram is meant for integers represented as (n + 1), so zero would be 010, one would be 0110, two would be 01110 and so on. As in my videos I represent numbers as (n), one is 010, two is 0110, ect., the diagram is indeed off by one. Sorry for the mix up and thanks for pointing that out!

It is about quantum computing (although I understand it's not obvious at first). You can find an explanation of why here: ua-cam.com/video/tHNCJuoqKu8/v-deo.html

It's a web based simulator created by a developer named Davy Wybiral. Here's the link if you'd like to give it a try: wybiral.github.io/quantum/

I agree

Yes, in the time spent thinking about this topic since making this video, I’ve become more convinced that the Many Worlds Interpretation is the best interpretation of quantum mechanics. Consider the following points: 1. What arguments are there for there being only one universe? The best one that I can think of is that it appears as if there is only one when you think back to a particular event, say for example who won the Euro Cup this year. You and everyone else you know can only remember one event happening, in this case Italy winning the Euro Cup. But what if there were parallel universes? In that case someone living in that other universe would also think only one outcome occurred, say instead England winning the Euro Cup. So for each person in a parallel universe it would appear as if there was one universe, since they couldn’t directly observe the other ones. So thinking there is only one universe could simply be an illusion of perspective, similar to why people once thought the sun revolved around the earth. So the fact that it appears there is one universe doesn’t necessarily mean there is just one; it could very easily just be an illusion of perspective. 2. If you believe there is only one universe you must answer this question: why can we not know with certainty what is going to happen in the future, even when we have maximum knowledge about a quantum system? If there is just one universe then for any given event there must only be one outcome right? So then with all our advances in technology why have we not been able to figure out what the single outcome will be? Even with simple quantum systems? For example, if I ask you who is going to win the Olympics this year, the most accurate way you could describe it would be by expressing the possible outcomes as probabilities. For instance, you may say the US has a 33% chance, China a 29% chance, Japan 26%, and so on. But if there is one universe, then would it be possible to know which outcome will happen with certainty if we had all the information about the system? You may say, there are too many variables to calculate who will win the Olympics with certainty, and you are right! So let's instead consider a very simple 3 qubit circuit in a quantum simulator pictured in this link below: www.dropbox.com/s/7ig9k0ap3fii7v3/QuantumCircuit.png?dl=0 So now that we have a very simple quantum system and do not have to worry about any problems with measurement since it's on a simulator, are we now able to know which outcomes will happen with certainty? No, the outcome is still expressed as a probability, |100> has a 25% chance, |101> a 25% chance, |110> a 25% chance and so on. If there is one universe, should not one outcome always be 100%? To quote Einstein on this problem: “God does not play dice!” This is the problem that The Many Worlds Interpretation so elegantly solves. It says that the full description of a quantum system is the sum total of all the probabilities of the wave function. So there is no need to explain why one outcome occurs instead of another, because all possible outcomes actually occur. So when you make an observation you really are only observing one small part of the whole system. Also, do not forget that you yourself are also a quantum system since you yourself are also built from atoms and electrons. As such, the best way to describe your interaction with a real quantum circuit would be to add the sum of total number of ‘versions’ of you who observe |000>, plus the number of ‘versions’ of who observe |001> plus the number who observe |010>, and so on, until you reach 100% (i.e fully describe a quantum interaction; no more dice!). And since the athletes and venues of the Olympics are also built from atoms and electrons, the best description of the system would be to say in 33% of the universes the United States will be the winner, in 29% of the universes Japan will win, in 26% China will win, and so on. Since there will be more universes where the US is the winner, it is more likely that you will end up as a version of you who observes the US winning, and less likely you will end up as a version of you that observes the Philippines winning the Olympics. As you can see by describing a quantum system as the sum total of all possibilities you can avoid the problem of explaining why in some quantum systems we cannot know which outcome will occur with certainty, since all outcomes actually occur. So even if you disagree with everything I wrote above, you must still answer this question. If there is only one universe, then why cannot we not know what that single outcome of a future event will be, even in a very simple quantum system with perfect measurements? 3. Observe how easily your mind can imagine parallel universes. You can very easily imagine England or Italy winning the Euro Cup. You can easily imagine the US, China, Japan or any other country winning the olympics. You can imagine what your life would have been like if you had chosen a different career, or hadn’t broken up with a particular partner. When you decide to buy insurance for example you are imagining the universes where you might be glad you made the purchase, or the probability of universes where you didn’t need it at all. Think about the different universes humans have created in books and movies, or the different future projections people have for the future of humanity. Not all you can imagine will actually occur of course, but the fact our minds can so easily think about parallel universes I believe gives us a hint to the structure of reality our brains evolved in. Your brain it would seem is highly evolved to calculate the multiverse. Parallel universes seem a strange idea at first, but not as much when you consider the fact you are thinking about parallel universes all the time. These are just general philosophical arguments though and a high level overview about how I think about the Everett Interpretation. Ultimately looking at quantum experiments (i.e double slit, beam splitter) is probably the best place to start for thinking about this. But it was nice to be able to get these thoughts out, so thanks for being the outlet to my long winded response! Let me know if you have any more questions or comments.

​@@travisgritter34971. Shifting the burden of proof. You have to prove parallel universes, we don't have to disprove it. 2. The fact we cannot predict the outcome of an experiment with certainty does not prove there are parallel universes. 3. Your argument is literally that because you can imagine something it must be real...just lol

No worries! Glad you found it helpful!

Hi Andrew! Thanks for you comment, it's very much appreciated! The quantum simulator I use is created by a developer named Davy Wybiral. You can find the link to the simulator here: qcsimulator.github.io/

Hi Qulaey, thanks for your question! No, there is no limit for the number of qubits that Grover’s Algorithm can use. The runtime for Grover’s Algorithm is O(sqrt(n)) where n is any positive natural number to infinity. The reason you are often seeing a 2 qubit oracle (with 4 possible states) is likely because 2 qubits makes for the easiest example to demonstrate the algorithm. Here’s an example of a 5 qubit Grover’s Algorithm for your convenience: www.travisgritter.me/quantum/?example=Grover%27s%20Algorithm That being said, the more qubits that are used in a real quantum computer the more unstable the quantum system becomes. So while there are no theoretical limits on the number of qubits that can be used in Grover’s algorithm, there are certainly practical limits as research into quantum computers continues. Hope that answers your question!

@@travisgritter3497 Thanks Travis I really appreciate the reply, In your example whats actually inside the "f7" and "grov" gates?

Theoretically - no limitation (If you have access to the required qubits) Practically - yes (Because all the cloud services that provide Quantum Computers only let you do maximum 1024 shots per call, You can do multiple calls obviously but it would require a lot of time and money)

Hi Roberto! I'm actively working on some more videos currently, so what kind of videos are you looking for exactly? Just ones without equations?

I had the same question.